Experimental Investigation of the Influence of Nanoparticles Adsorption and Transport on Wettability Alteration for Oil Wet Berea Sandstone

Abstract

Wettability alteration has been proposed as an important Enhanced Oil Recovery (EOR) mechanism for nanoparticles suspension. For better understanding nanoparticles adsorption behavior inside core and its effect on wettability, a series of wettability measurement experiments for oil wet Berea sandstone were conducted, where the core plugs were treated by different concentration and type of nanoparticles suspensions. Nanoparticles transport experiments also were performed for core plugs with injection of varying concentration and type of nanoparticles suspensions. Pressure drop across the core plug during injection was recorded to evaluate nanoparticles adsorption and retention inside core, as well as desorption during brine post-flush. Both hydrophilic silica nano-structure particles and hydrophilic silica colloidal nanoparticles were utilized in above two experiments. Contact angle between oil and nanofluids measurements also were performed to investigate the effect of nanoparticles on wettability.The results of wettability alteration experiments indicated that hydrophilic nanoparticles have ability of making oil wet Berea sandstone to be more water wet, and the higher concentration the more water wet will be. Different types of nanoparticles have different effect on the wettability alteration process. The results from contact angle measurements were consistent with wettability index measurements. For nanoparticles transport experiments, the results showed that the nanoparticles undergo both adsorption and desorption during injection. Pressure drop curves showed that absorption and retention of nano-structure particles inside core was significant, while colloidal nanoparticles did not adsorb much. Permeability impairment was observed during nano-structure particles fluid injection, but on the contrary colloidal nanoparticles dispersion injection made core more permeable.

Mechanism governing nanoparticle flow behaviour in porous media: insight for enhanced oil recovery applications

“…TEM analysis revealed that nanoparticles where attached to the pore walls. Again, the work of Li and Torsaeter [34] was an improved study on wettability alteration and they confirmed earlier reports. Ju et al [26] using a physical model, mathematical model, and a numerical simulator were able to increase recovery by 15.38% when treated with waterwetting wettability control agent (IWWCA) and increasing the oil-wetting wettability control agent (IOWCA) improves recovery (60-80%) in water injection rate.…”

“…Adsorption and desorption takes place depending on the attraction and repulsion force between the porous media wall and nanoparticles. During the flow of nanoparticles through porous media, mainly diffusion, convection and hydrodynamics play major role [34]. However, the adsorption of nanoparticles onto rock surface is influenced by born repulsion and controlled by hydrodynamic forces.…”

“…From the result of the visualization experiment, they concluded thus; that nanoparticles were deposited and adsorbed at the surface, which led to reduction in permeability by blocking the pore throat of the model. Li and Torsaeter [34] investigated the performance of nanoparticles in oil recovery, they reported that adsorption of nanoparticles in glass micro model may cause plugging of the channel and thereby reduce permeability by changing the pressure drop during the experimental process.…”

Effect of Various Silica Nanofluids: Reduction of Fines Migrations and Surface Modification of Berea Sandstone

“…The small size and high specific surface area of NP offer unique advantages like allowing them to easily pass through pore throats and enhanced interaction in the reservoir even with a small quantity of NP. NPs have displayed the potential to act as surface modifiers that could alter the wettability and reduce the oil/water interfacial tension leading to better mobility of the oil phase [1][2][3][4][5][6][7] and reduce fines migration [8,9]. Recent laboratory studies have indicated that nanofluids, which are colloidal dispersions of NP in a dispersing medium have the potential to increase oil recovery [2,7,[10][11][12][13].…”

“…When NPs are introduced into porous medium, different processes may take place such as adsorption, desorption, blocking, transportation and aggregation [4]. The adsorption phenomenon could be reversible (desorption) during the transport of NP in the porous medium [20].…”